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Networking overview

One of the reasons Docker containers and services are so powerful is that
you can connect them together, or connect them to non-Docker workloads. Docker
containers and services do not even need to be aware that they are deployed on
Docker, or whether their peers are also Docker workloads or not. Whether your
Docker hosts run Linux, Windows, or a mix of the two, you can use Docker to
manage them in a platform-agnostic way.

This topic defines some basic Docker networking concepts and prepares you to
design and deploy your applications to take full advantage of these
capabilities.

Scope of this topic

This topic does not go into OS-specific details about how Docker networks
work, so you will not find information about how Docker manipulates iptables
rules on Linux or how it manipulates routing rules on Windows servers, and you
will not find detailed information about how Docker forms and encapsulates
packets or handles encryption. See Docker and iptables.

In addition, this topic does not provide any tutorials for how to create,
manage, and use Docker networks. Each section includes links to relevant
tutorials and command references.

Network drivers

Docker’s networking subsystem is pluggable, using drivers. Several drivers
exist by default, and provide core networking functionality:

bridge: The default network driver. If you don’t specify a driver, this is
the type of network you are creating. Bridge networks are usually used when
your applications run in standalone containers that need to communicate. See
bridge networks.
host: For standalone containers, remove network isolation between the
container and the Docker host, and use the host’s networking directly. See
use the host network.
overlay: Overlay networks connect multiple Docker daemons together and
enable swarm services to communicate with each other. You can also use overlay
networks to facilitate communication between a swarm service and a standalone
container, or between two standalone containers on different Docker daemons.
This strategy removes the need to do OS-level routing between these
containers. See overlay networks.
ipvlan: IPvlan networks give users total control over both IPv4 and IPv6
addressing. The VLAN driver builds on top of that in giving operators complete
control of layer 2 VLAN tagging and even IPvlan L3 routing for users
interested in underlay network integration. See IPvlan networks.
macvlan: Macvlan networks allow you to assign a MAC address to a container,
making it appear as a physical device on your network. The Docker daemon
routes traffic to containers by their MAC addresses. Using the macvlan
driver is sometimes the best choice when dealing with legacy applications that
expect to be directly connected to the physical network, rather than routed
through the Docker host’s network stack. See
Macvlan networks.
none: For this container, disable all networking. Usually used in
conjunction with a custom network driver. none is not available for swarm
services. See
disable container networking.
Network plugins: You can install and use
third-party network plugins with Docker. These plugins are available from
Docker Hub
or from third-party vendors. See the vendor’s documentation for installing and
using a given network plugin.

Network driver summary

User-defined bridge networks are best when you need multiple containers to
communicate on the same Docker host.
Host networks are best when the network stack should not be isolated from
the Docker host, but you want other aspects of the container to be isolated.
Overlay networks are best when you need containers running on different
Docker hosts to communicate, or when multiple applications work together using
swarm services.
Macvlan networks are best when you are migrating from a VM setup or
need your containers to look like physical hosts on your network, each with a
unique MAC address.
Third-party network plugins allow you to integrate Docker with specialized
network stacks.